Heat exchanger, in particular for an internal combustion engine

ABSTRACT

A heat exchanger, in particular for an internal combustion engine, comprising a plurality of flat tubes that extend parallel to one another and are each oriented with a longitudinal side in a primary flow direction of a fluid, and a base, wherein a plurality of passages into which each of the flat tubes terminate are provided in the base, wherein at least four rows of flat tubes are arranged one behind the other in the primary flow direction, all of which terminate in the base.

This nonprovisional application claims priority under 35 U.S.C. §119(a) to German Patent Application No. DE 10 2009 032 782.7, which was filed in Germany on Jul. 10 2009, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a heat exchanger, in particular for an internal combustion engine.

2. Description of the Background Art

From the practice of constructing heat exchangers for commercial vehicles and passenger vehicles it is known to arrange flat tubes in a stack in two parallel rows one behind the other, with the flat tubes of the two rows terminating in the same base of a header located on the end. In this arrangement, a primary flow direction of a fluid, for example the slipstream, flowing around one of the flat tubes, extends in a depth direction parallel to the longitudinal sides of the flat tubes.

In the event of requirements calling for the installed depth of the exchanger network to be increased in the depth direction, it has previously been the practice to arrange multiple single-row or double-row heat exchangers or networks of exchanger tubes into a set.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to specify a heat exchanger that is compact while being simple and economical to construct.

As a result of arrangement according to an embodiment, of at least four rows of flat tubes in the primary flow direction, an especially great depth of the heat exchanger can be achieved, so that its construction is especially compact. Having all of the rows of flat tubes terminate in the same base permits an especially economical construction while in a simple manner avoiding intermediate spaces that are unfavorable for heat transfer.

In an embodiment of the invention, the number of rows is precisely four. It has been determined that a very large number of rows entails an increasing complexity in the fixturing of the heat exchanger, and the reject rates become higher. An optimal number of rows of tubes together with a large depth of the network and low reject rate is optimally achieved when the number of rows of tubes is four.

In an embodiment, the heat exchanger can be designed on the basis of aluminum, for example from solder-plated aluminum sheets. A fixturing of the flat tubes and bases normally takes place here, with the addition—depending on design—of aluminum boxes to complete the header. This fixtured or mechanically preassembled unit is placed in a soldering oven and is soldered to produce an integrally bonded, fluid-tight heat exchanger.

In another embodiment of the invention, each of the flat tubes of a row is aligned with a flat tube of a subsequent or preceding row. This results in optimal utilization of construction space and an especially simple and effective way to arrange ribs between the flat tubes.

In an embodiment of the invention, which may be preferred because of particular requirements, a maximum depth of the plurality of flat tubes in the primary direction of flow is at least as large as a maximum width of the flat tubes transverse to the primary direction of flow. This also includes the possibility of an essentially square cross-section of the tube network. In an embodiment that is an alternative as a function of requirements, provision can, in contrast, be made that a maximum depth of the plurality of flat tubes in the primary direction of flow is smaller than a maximum width of the flat tubes transverse to the primary direction of flow.

The flat tubes can have at least one division running in their longitudinal direction, in particular in the form of a crease-like indentation. By this means, an improvement in exchanger performance and/or an increase in pressure resistance is ensured in general. In an especially preferred detailed design, the passages have at least one projection corresponding to the indentation. In addition to the task of sealing between the passage and the flat tube inserted therein, the projection can also achieve especially good guidance and retention of the course of fixturing.

Depending on requirements, an inventive heat exchanger may be a radiator or an intercooler of an internal combustion engine. It can also be an evaporator of an air conditioner or a condenser/gas cooler of an air conditioner.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 shows a three-dimensional view of a base of an inventive heat exchanger; and

FIG. 2 shows a top view of the base from FIG. 1.

DETAILED DESCRIPTION

A preferred exemplary embodiment of a heat exchanger according to the invention comprises a unit, fixtured from solder-plated aluminum sheets and flat tubes, that is soldered together into an integral unit in a soldering oven.

FIG. 1 shows a base 1 of this heat exchanger as the central component. Not shown are a box by which the base 1 is completed to form a header, and the flat tubes inserted into the base 1. The flat tubes (not shown) are made from a solder-plated aluminum sheet as folded tubes, each of which has a central indentation to form a web dividing the flat tube into two chambers. Alternatively, the flat tubes can also be formed as extruded profiles.

Passages 2 in the form of punched, slot-shaped holes are made in the base 1. The passages 2 each have at their centers projections 2 a that extend symmetrically from the edge and correspond to the indentations (not shown) of the flat tubes.

In a depth direction T, which at the same time is the primary flow direction of a fluid flowing around one of the flat tubes, four rows a, b, c, d of flat tubes are each arranged one behind the other. The width direction B extends in the stacking direction of a given row of the flat tubes, and the longitudinal direction L extends in the direction of the longitudinal extent of the flat tubes, or perpendicular to the plane of the base 1.

In the present case by way of example, each of the rows a, b, c, d comprises a stack of fourteen flat tubes, which extends in the transverse direction or in the width direction B of the heat exchanger.

It can be seen that all of the flat tubes of one of the rows a, b, c, d are each in alignment with a flat tube of a subsequent or preceding row a, b, c, d. The longitudinal sides of the flat tubes extend parallel to the depth direction T.

All of the flat tubes together form the network of the heat exchanger. The exchanger network in the present case is longer in the depth direction T than in the width direction B (refer, in particular, to FIG. 2), so that a maximum depth TM in the plurality of flat tubes in the primary flow direction is greater than a maximum width BM of the flat tubes transverse to the primary flow direction T.

In the present exemplary embodiment, each of the rows a, b, c, d is surrounded by an embossed edge 3, which improves the stiffness of the base 1.

The base of the exemplary embodiment shown is the base of a radiator, wherein the coolant flows through the flat tubes, and cooling air, such as, e.g., slipstream, flows around the tubes. In an alternative embodiment, this could also be an intercooler or a different heat exchanger, in particular for an internal combustion engine.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. 

1. A heat exchanger for an internal combustion engine, the heat exchanger comprising: a plurality of flat tubes that extend parallel to one another and are each oriented with a longitudinal side in a primary flow direction of a fluid; a base having a plurality of passages into which each of the flat tubes terminate; at least four rows of flat tubes arranged one behind the other in the primary flow direction, all of the rows terminating in the base.
 2. The heat exchanger according to claim 1, wherein the number of rows is precisely four.
 3. The heat exchanger according to claim 1, wherein each of the flat tubes of a row is aligned with a flat tube of a subsequent or preceding row.
 4. The heat exchanger according to claim 1, wherein a maximum depth of the plurality of flat tubes in the primary direction of flow is at least as large as a maximum width of the flat tubes transverse to the primary direction of flow.
 5. The heat exchanger according to claim 1, wherein a maximum depth of the plurality of flat tubes in the primary direction of flow is smaller than a maximum width of the flat tubes transverse to the primary direction of flow.
 6. The heat exchanger according to claim 1, wherein the flat tubes have at least one division running in a longitudinal direction, the division being in the form of a crease-like indentation.
 7. The heat exchanger according to claim 1, wherein the passages have at least one projection corresponding to the indentation.
 8. The heat exchanger according to claim 1, wherein the heat exchanger is a radiator, an intercooler, an evaporator of an air conditioner, or a condenser/gas cooler of an air conditioner. 